[SCSI] Update the SCSI state model to allow blocking in the created state

Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).

Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition.  Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index cc46652e4658..b49e725be039 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -42,9 +42,11 @@ enum scsi_device_state {
                                  * originate in the mid-layer) */
         SDEV_OFFLINE,           /* Device offlined (by error handling or
                                  * user request */
-        SDEV_BLOCK,             /* Device blocked by scsi lld.  No scsi 
-                                 * commands from user or midlayer should be issued
-                                 * to the scsi lld. */
+        SDEV_BLOCK,             /* Device blocked by scsi lld.  No
+                                 * scsi commands from user or midlayer
+                                 * should be issued to the scsi
+                                 * lld. */
+        SDEV_CREATED_BLOCK,     /* same as above but for created devices */
 };
 
 enum scsi_device_event {
@@ -393,11 +395,13 @@ static inline int scsi_device_online(struct scsi_device *sdev)
 }
 static inline int scsi_device_blocked(struct scsi_device *sdev)
 {
-        return sdev->sdev_state == SDEV_BLOCK;
+        return sdev->sdev_state == SDEV_BLOCK ||
+                sdev->sdev_state == SDEV_CREATED_BLOCK;
 }
 static inline int scsi_device_created(struct scsi_device *sdev)
 {
-        return sdev->sdev_state == SDEV_CREATED;
+        return sdev->sdev_state == SDEV_CREATED ||
+                sdev->sdev_state == SDEV_CREATED_BLOCK;
 }
 
 /* accessor functions for the SCSI parameters */